/**
 * 删除排序链表中的重复元素
 */


function deleteDuplicates(head) {
    let l = head
    if(l ===null ) return null
    while (l.next) {
        if(l.val === l.next.val) {
            l.next = l.next.next
        }else {
            l = l.next
        }
    }
    return head
}
